The effect of placement and light conditions during foliar application of
Insol U fertilizer on gas exchange, yield and the quality of spinach (Spinacia oleracea L.)
Edward Borowski, Sławomir Michałek
Department of Plant Physiology
University of Life Sciences in Lublin
Akademicka 15, 20-950 Lublin, Poland
Pot experiments conducted in a growth chamber studied the effectiveness of foliar
fertilization of spinach (Spinacia oleracea L.) with macro- and microelements in
the form of a 1% water solution of Insol U fertilizer applied with fluorescent light
of the PAR intensity of 200 μmol m-2 s-1 and with dispersed daylight of the
intensity of 600 μmol m-2 s-1. Insol U was applied three times, supplied on the
upper, lower or both sides of the leaf blades. The control consisted of plants
sprayed with distilled water. The obtained results pointed out that foliar
fertilization of spinach with Insol U significantly increased the leaf gas exchange,
the yield of the fresh leaf mass, the content of vitamin C, chlorophyll, carotenoids,
as well as potassium and phosphorus in the leaves. The application of the fertilizer
onto the upper and the lower side of the leaf blade had the most positive effect on
the analysed property of the leaves. Independently of the side leaf, the application
of the fertilizer at a higher light intensity had a significantly better consecutive
effect on all the analysed properties of the leaves.
Borowski E., Michałek S., 2009. The effect of placement and light conditions during foliar application of
Insol U fertilizer on gas exchange, yield and the quality of spinach (Spinacia oleracea L.).
Folia Horticulturae 21/1: 61-71.